fix(nemesis): empty return from get_non_system_ks_cf_list() raise Uns…

…upporttedNemesis

In some case we don't have CQL based tables in nemesis (i.e. alternator tests),
and we want those to be skipped automaticlly, and not reported as errors.

sdcm/nemesis.py

@@ -351,7 +351,7 @@ def _destroy_data_and_restart_scylla(self):
         ks_cfs = get_non_system_ks_cf_list(loader_node=random.choice(self.loaders.nodes),
                                            db_node=self.target_node)
         if not ks_cfs:
-            raise NoKeyspaceFound(
+            raise UnsupportedNemesis(
                 'Non-system keyspace and table are not found. CorruptThenRepair nemesis can\'t be run')
 
         # Stop scylla service before deleting sstables to avoid partial deletion of files that are under compaction
@@ -701,7 +701,8 @@ def _modify_table_property(self, name, val, filter_out_table_with_counter=False,
 
         keyspace_table = random.choice(ks_cfs) if ks_cfs else ks_cfs
         if not keyspace_table:
-            raise ValueError('Non-system keyspace and table are not found. ModifyTableProperties nemesis can\'t be run')
+            raise UnsupportedNemesis(
+                'Non-system keyspace and table are not found. ModifyTableProperties nemesis can\'t be run')
 
         cmd = "ALTER TABLE {keyspace_table} WITH {name} = {val};".format(
             keyspace_table=keyspace_table, name=name, val=val)
@@ -1066,8 +1067,9 @@ def toggle_table_ics(self):
         ks_cfs = get_non_system_ks_cf_list(loader_node=random.choice(self.loaders.nodes),
                                            db_node=self.target_node)
         if not ks_cfs:
-            self.log.error('Non-system keyspace and table are not found. toggle_tables_ics nemesis can\'t run')
-            return
+            raise UnsupportedNemesis(
+                'Non-system keyspace and table are not found. toggle_tables_ics nemesis can\'t run')
+
         keyspace_table = random.choice(ks_cfs)
         keyspace, table = keyspace_table.split('.')
         cur_compaction_strategy = get_compaction_strategy(node=self.target_node, keyspace=keyspace,
@@ -1423,6 +1425,8 @@ def _parse_toppartitions_output(output):
 
         def generate_random_parameters_values():  # pylint: disable=invalid-name
             ks_cf_list = get_non_system_ks_cf_list(self.loaders.nodes[0], self.cluster.nodes[0])
+            if not ks_cf_list:
+                raise UnsupportedNemesis('User-defined Keyspace and ColumnFamily are not found.')
             try:
                 ks, cf = random.choice(ks_cf_list).split('.')
             except IndexError as details: